Mechanical work extraction from an error-prone active dynamic Szilard engine

TL;DR

This paper analyzes a realistic active Szilard engine operating with an active particle, revealing how measurement errors influence work, power, and efficiency, and demonstrating violations of Landauer's bound with optimized cyclic operation.

Contribution

It provides a comprehensive analysis of a realistic active Szilard engine, including effects of measurement errors and conditions for positive work and efficiency, with novel insights into information efficiency and engine optimization.

Findings

Finite measurement accuracy affects work and power output.

Engine can violate Landauer's bound on efficiency.

Cyclic operation enhances information efficiency.

Abstract

Isothermal information engines operate by extracting net work from a single heat bath through measurement and feedback control. In this work, we analyze a realistic active Szilard engine operating on a single active particle by means of steric interaction with an externally controlled mechanical element. In particular, we provide a comprehensive study of how finite measurement accuracy affects the engine's work and power output, as well as the cost of operation. Having established the existence of non-trivial optima for work and power output, we study the dependence of their loci on the measurement error parameters and identify conditions for their positivity under one-shot and cyclic engine operation. By computing a suitably defined information efficiency, we also demonstrate that this engine design allows for the violation of Landauer's bound on the efficiency of information-to-work conversion. Notably, the information efficiency for one-shot operation exhibits a discontinuous transition and a non-monotonic dependence on the measurement precision. Finally, we show that cyclic operation improves information efficiency by harvesting residual mutual information between successive measurements.